Food Detection and Feeding Behavior of Three Species of Household Cockroaches, Blatella germanica (L.), Periplaneta americana (L.), and Supella longipalpa (F.)

Abstract

German cockroaches (Blatella germanica L.), American cockroaches (Periplaneta americana L.,) and brown-banded cockroaches (Supella longipapla F.) are the most important urban insect pests. The food detection and feeding behavior of these cockroaches are varied and depend on different factors. German cockroach starts feeding between 7:00–10:00 pm and 4:00–5:00 am, whereas the American cockroach starts within the first few hours of darkness followed by an inactive period in the latter part, and throughout the light period. The calling in females of brown-banded cockroaches followed periodicity and peak calling occurs in the scotophase. Likewise, the behavioral response of male brown-banded cockroaches was at a peak in the scotophase. German cockroach compound eye is sensitive to blue-green portion of the spectrum (major) and ultraviolet (UV) (minor). The compound eye of the American cockroach received the blue-green and violet (or ultraviolet) regions of the spectrum. Information on the compound eye sensitivity of brown-banded cockroaches is limited. The possession of specific hygroreceptors could play an important role in both German and American cockroaches. The German cockroach preferred carbohydrates food and consumed more containing starch, glucose, sucrose, mannitol, maltose, sorbitol, or glycerol. Very limited studies were carried out to determine the food detection ability and the feeding behavior of the brown-banded cockroach. Future studies should be directed toward the color preferences of the brown-banded cockroach.

1. Introduction

German cockroaches (Blatella germanica L.) (Dictyoptera: Blattellidae), American cockroaches (Periplaneta americana L.) (Dictyoptera: Blattidae), and brown-banded cockroaches (Supella Longipalpa F.) (Dictyoptera: Blattellidae) are the most important urban insect pests, cause nuisance in and around the house. Cockroaches, their body parts, saliva, and protein produced by them cause allergies and severe asthma as well [1, 2, 3]. The German cockroach is the most abundant and has the widest distribution. The brown-banded and American cockroaches follow the German cockroach with respect to importance in cosmopolitan distribution [4].

All three species acted as vectors to transmit pathogenic bacteria [5, 6, 7, 8, 9, 10]. They are nocturnal in habit; however, their peak activity varies during scotophase. Wang and Bennett [11] found that the diet history of cockroach strains influenced the feeding behavior of German cockroaches. They further stated that cockroaches grown on a mixed diet consumed less gel bait than those reared only on a rodent diet. Insecticide bait formulations have been used effectively used for managing German cockroach populations [12, 13]. A similar principle has been used for the other two species of household cockroaches. In recent years, gel bait formulation has been highly effective in controlling German cockroach populations [14]. These baits are toxic and normally contain a sugar phagostimulant, as well as active ingredients that are incorporated into the food matrix [15]. The major influencing factors for bait efficacy are the attractiveness [16], palatability, and toxicity of the active ingredients [17]. It has been stated that field-collected German cockroaches develop an aversion to glucose [18] and subsequently reject the food containing this compound [19].

Field-collected gel bait-resistant Cincy strain of German cockroaches showed resistance with Avert (0.05% abamectin), maxforce FC (0.01% fipronil), and pre-empt (2.15% imidacloprid) gel baits [20, 21]. Wang et al. [20] further mentioned that the aversion Cincy strain exhibited avoidance behavior on agar gel bait that contained fructose, glucose, maltose, and sucrose, which were commonly used as phagostimulants. Modification of those inert ingredients improved the efficacy of fipronil gel. Milio et al. [22] stated that 1.65% hydramethylnon bait stations provided moderate control of American cockroaches in poultry house feed rooms. However, Holbrook et al. [23] found that German cockroaches showed resistance to fipronil even though their ancestors were never exposed to it and showed resistance to the cyclodienes, which were formerly used for cockroach control. Similarly, it had been reported that field-collected bait resistant (Cincy) strain of German cockroaches showed behavioral resistance to avert (0.05% abamectin), maxforce FC (0.01% fipronil) [20] and avert (0.05% abamectin), maxforce FC (0.01% fipronil), and pre-empt (2.15% imidacloprid) gel baits [21]. Moreover, both maxforce FC containing fipronil and hydramethylnon were not effective for the control of bait aversion (Miami) strain of German cockroaches [24]. Similarly, in Taiwan, German cockroaches collected from households and hospitals in Kaohsiung area, south Taiwan develop resistance against three insecticides propoxur, chlorpyrifos, and cypermethrin [25]. Agrawal et al. [26] found that the synthetic pyrethroid combination of imiprothrin 0.07% + cypermethrin 0.2% aerosol caused only 20% reduction of German and American cockroach infestation 12 weeks after treatment. Recently, Fardisi et al. [27] stated that both insecticide-susceptible lab strains and field strains of German cockroaches exhibited a varying level of resistance to indoxacarb, fipronil, acetamiprid, beta-cyfluthrin, bifenthrin, and lambda-cyhalothrin. Hydramethylnon and imidacloprid insecticides could not achieve more than 90% mortality for the field strain, although there was no survivorship difference between the field strains and lab strains with the two insecticides. Field strains showed the lowest resistance to boric acid, abamectin, dinotefuran, clothianidin, thiamethoxam, and chlorfenapyr. Liang et al. [28] identified that prolonged exposure to the German cockroach showed physiological resistance to baits containing fipronil or indoxacarb. They further determined that cockroaches exposed to fipronil-containing gel bait exhibited cross-resistance to indoxacarb-containing gel bait.

In recent years, most of the studies have been focused on the development of new gel bait and efficacy tests of gel baits. However, limited studies have been carried out to determine attractants food, food detection, and feeding behavior of household cockroaches. Thus, the study was done to collect and discuss information on food detection and feeding behavior of the German cockroach, American cockroach, and brown-banded cockroach.

2. Circadian rhythm among three cockroach species

Generally, cockroaches are nocturnal in habit. Previous researchers have found that German cockroaches, remain in a temporary or permanent sanctuary or refuge for pests to live and or rest (harborage) during the day or other periods of light and become active during the night. They obtained a mixed diet from their foraging and are generally omnivorous [13, 29]. However, Tsai and Lee [30] determined that mated females could not express a circadian locomotor rhythm. In another study, it was found that the German cockroaches exhibited a bimodal activity response when they were exposed to natural light conditions and the activity began at sunset and reached a peak several hours after the onset of darkness [31]. Moreover, it was also found that a second peak activity occurred shortly before the light period began and was more noticeable under natural light than under artificial light [31].

In German cockroaches, daily patterns of activity generally varied between 22 and 26 hours [13]. External cues synchronize the activity periods and various periodic events typically serve as cues to entrain behavioral rhythms [13]. Adult male German cockroaches are more active than nymphs and adult females when foraging for food, water, and nest, as well as searching for mates [31]. The daily rhythm of male German cockroaches followed two phases, scotophase and photophase. German cockroach feeding behavior occurred between 7:00–10:00 pm and 4:00–5:00 am. The feeding behavior of German cockroaches involved swinging the antenna followed by touching the food [32]. Their activities increased rapidly at the onset of the scotophase from 14:00 hours to a peak at 17:00 hours and decreased rapidly afterward. Shortly before the photophase commences, there was a second rush of activity between 22:00 hours and 23:00 hours [31]. Furthermore, Fuchs [33] determined that the activity observed from German cockroaches peaked 3 h before the scotophase and 1 h before the photophase only when they were in the nest. Again, activity reached its highest peak immediately after the onset of the scotophase. He further revealed that long-range foraging occurred at specific times, whereas short-range foraging is common behavior of German cockroaches. In the case of females, their activity decreased to a minimum and there was no significant difference in activity during scotophase and photophase. The periods of maximal activity of the gravid females were often during photophase [31].

Sommer [34] examined substrate vibrations and the presence of other German cockroaches as potential signal and determined that the activity of cockroaches and individual rhythm could be fully synchronized with vibrations (50 Hz for 12 hours). Moreover, he found that cockroaches dragged by photoperiod could not be synchronized with such 50 Hz vibrations.

Silverman [35] stated that the frequency of feeding and drinking of adult German cockroaches was determined by the distance from the nest to resource. Moreover, the cockroaches used a step-by-step manner to explore food patches, first, they search for food nearby the nest then they will move farther after the depletion of the nearest food [36]. Moreover, Nalyanya et al. [37] stated that both adult males and first instar German cockroaches chose shelters that were nearby the attractant-treated area and the furthest distance from the repellent-treated area. They further mentioned that the cockroach consumed the highest amount of food, and mortality was also the highest when the insecticide bait was placed near the preferred shelter.

In the case of American cockroaches, the onset of activities occurred within the first few hours of darkness, followed by a relatively inactive period in the later part and throughout most of the light period. However, adult females did not exhibit activity rhythms related to the lighting regimen (a specific photoperiod-12 L: 12 D h) [38]. In another experiment, it was determined that American cockroaches had diurnal locomotory activity correlated with alternating light and dark period; however, there was no correlation with temperature and humidity fluctuation. Alternate period of 24 h light and dark maintained a similar rhythm and activity which coincided with the beginning of day or night [39].

In the American cockroach, Lipton and Sutherland [38] demonstrated that the onset of feeding occurs soon after the onset of darkness. Moreover, Harker [40] found that the ocelli of American cockroaches were linked with light and darkness and also directly correlated with the establishment of the rhythm. Loss of rhythm was found when painting over the eyes and ocelli of the cockroaches. There was no direct connection between the hunger cycle and the rhythm activities.

The brown-banded cockroach, calling occurred discontinuously and followed a diel pattern primarily during the scotophase, in a 12 L: 12 h D photoperiod and after transfer to continuous light or dark conditions [41].

3. Food searching behavior

Ebeling et al. [42] reported that there was an inverse relationship between population density and exploratory behavior in the male German cockroach, which was accredited by the presence of an aggregation pheromone in the nest. Raubenheimer and Jones [29] mentioned that the German cockroach can balance the micronutrient intake by selecting a mixed diet from foods. The authors further stated that the ability to distinguish food of different nutritional values could be due to specific nutrient learning that was developed slowly on nutritionally imbalanced food. In general, when there are imbalanced foods, it shows slowed development and increased mortality in herbivores; however, the German cockroaches show well adapted variation of ingested nutrients. Eating and drinking activities of B. germanica were related to the more general circadian activity phases [31].

Similarly, Gadd and Raubenheimer [43] reported that American cockroaches were able to associate food odors with proteins. Moreover, it was determined that this species exhibited a spontaneous initial preference for vanilla over menthol [44].

Nymphs of brown-banded cockroaches self-selected a 15.5:84.5 protein: carbohydrate diet when they were reared with two imbalanced diet cubes. One contained absence of protein, while the other contained the absence of carbohydrates [45].

4. Eating and drinking behavior of cockroaches

The German cockroach is nocturnal in habit and leaves its shelter for foraging at night. The development stage of individual cockroaches is determined by their eating and drinking habits [46]. The population of B. germanica is distributed in contiguous patterns and forms aggregates. There are no differences between males and nongravid females, but gravid females stayed mostly in the shelter and were less mobile [47]. Durbin and Cochran [48] observed that mortality increased when there was a deprivation of both food and water, which ultimately delayed the reproductive cycle. They reduced oothecal hatch in German cockroaches. Females survived much longer without food. Moreover, time spent on food and water was not much different for males and gravid females. Males foraged for food or water at least once in 7 days out of 10 days, whereas gravid females foraged actively on fewer than three days. With their fat and water reserves, female German cockroaches are well-suited to survive without food on a temporary basis [48].

The increased need for water also helped explain the behavior of most cockroaches to frequent water sources rather than solid food sources. The possession of specific hygroreceptors could play an important role in American cockroaches [31].

In the absence of drinking water, the nymphs of brown-banded cockroaches survived significantly longer than German cockroach nymphs. The capability of brown-banded nymphs was higher than German cockroach nymphs for producing and utilizing extra metabolic water from food [49]. Moreover, female, brown-banded cockroaches, when fed a 5% protein diet consumed less than fed either 25% protein or commercial rat food. Adult cockroach performance was also directly correlated with dietary protein levels and those females who died rapidly and were fed 65% protein [50].

5. Effect of population density on feeding and drinking behavior

It was found that male German cockroaches drink more at the low population density, although there was no overall effect of population density on feeding or drinking events [33].

Silverman [35] observed that when resources were farther away from the shelter the number of drinking and eating bouts increased. It was higher and took longer than at lower German cockroach population densities. If food and water were close to the shelter, shorter and fewer drinking bouts occurred under crowded conditions. This could be a reaction to increased competition at the water source and could relate to the interruption of drinking under high-density conditions. Under the crowded condition, more foraging occurred even if the resource was placed far from the harborage [35].

6. Factors affecting foraging and feeding behaviors

The age of German cockroaches was also influenced by the foraging behavior; adults and large instar (fifth and sixth instar) searched and found food sources first before the small instars [51]. Ballard et al. [52] determined that male German cockroaches were more active and explored more than females. Cochran [53] identified that feeding and drinking activity peaked during the egg maturation period and ended sharply at the appearance of egg capsules. However, Silverman [35] mentioned that nongravid female and male German cockroaches fed and drank more often than gravid females.

Cockroach feeding was affected by sex, age, and reproductive condition. The feeding behaviors of female B. germanica differed from nymph and adult males [54]. Males and unmated females of German cockroaches often responded to food odors from short distances, and they ate about 1–3 mg of food per day. Males who copulated twice a week ate more and died earlier than males that mated only once a week. In the case of females, different stages of reproductive cycles, carry different nutritional demands. Females, which were fed a low-protein diet, were able to increase consumption for supporting their normal growth and reproduction, whereas those fed with a high-protein diet increased mortality and decreased consumption and reproduction [55]. Peak feeding and drinking occurred during the egg maturation period and sharply ended when the egg case was apparent. Females feed and drink sparingly during the egg case-carrying period [53].

7. Visual sensitivity attractant color

Low-intensity red light is used to observe foraging and mating behavior of German cockroaches [56]. German cockroaches saw light with their compound eyes and received light through ocelli and dermal photoreceptors [57]. Koehler et al. [56] determined that German cockroaches had a color vision and the dorsal part of the compound eye had two peak sensitivities. The main visual wavelength spectrum was in the blue-green portion of the spectrum (490 nm), while the minor one was in the ultraviolet (UV) (365 nm). The UV light stimulated the highest level of locomotion, while green light stimulated about 30% and gold and red light did not affect locomotion.

Walther [58] mentioned that the eyes of P. americana contained at least two kinds of receptors. They were stimulated by the blue-green and violet (or ultraviolet) regions of the spectrum. Cockroaches contain compound eyes, which bear several kinds of receptor stimulated between 316 and 704 nm [59]. The spectral sensitivities of the dorsal ocelli of American cockroaches were measured using electrophysiological methods. Renowned showed that the waveform of the electrical response (ERG) of dark-adapted American cockroach ocellus was dependent on the intensity, but not on the wavelength of stimulating light. Moreover, they determined that the cockroach ocellus appeared to possess a single photoreceptor type, maximally sensitive at about 500 mμ [60].

8. Food attractant

Blattella germanica is oriented to food or water only if they came close to it after they began foraging, particularly after being deprived of food or water for a few days [31].

Cockroaches survived for long periods of time without food or water. B. germanica lived significantly longer if they have only food with access to water [31]. Willis and Lewis [61] reported that at 40% RH, without food and water, B. germanica survived up to 8 days, whereas females survived up to 13 days. Similarly, at 70% RH, females can survive up to 28 days without food or water. Water was required more critically than food for German cockroaches. Male B. germanica could not survive more than 9–10 days, but females could survive with access to water and without food for up to 45 days.

It was reported that after a carbohydrate meal, enzymes digested the sugars and the crops cleared within 48 hours. Sugar helped to increase the number of feeding episodes because of efficient digestion and the emptying of carbohydrates from the crop. Since German cockroaches preferred containing carbohydrates, bait consumption also increased by including substances, such as starch, glucose, sucrose, mannitol, maltose, sorbitol, or glycerol [4].

Karimifar [62] determined that peanut butter and beer were the most promising food source having semiochemicals that mediated the attraction of German cockroach. The molting and reproduction behavior of German cockroaches is regulated by food [46]. Food also played an important role in the temporal and spatial distribution of population densities of the German cockroach [36, 47].

Nalyanya et al. [16] found that bread was second to Maxforce gel for attracting male German cockroaches in olfactory assays. It was stated that in trapping studies in apartments, bread was used frequently and often mixed with beer [63, 64, 65]. It was identified that German cockroach baits are the mixture of odor or pheromone lures that attract insects [66].

Ballard and Gold [67] tested German cockroach attractiveness toward white bread, M. Sticky Chrysalis powder, Mr. Sticky Roach Bait, no bait, boiled raisins, potato, apple, dry dog food, German cockroach feces, German cockroach, dry yeast, banana, and Osage orange and found that the cockroaches were attracted significantly toward white bread and Osage orange.

Lofgren and Burden [68] stated that two percent Dipterex bait and powdered sugar showed the greatest attractiveness toward German cockroaches. Dextrin and corn starch alone or in combination were the most attractive to nymphs of American cockroaches in laboratory conditions. Similarly, it was found that German and American cockroaches were attracted to common foodstuffs, such as soft drink syrups, brown sugar, molasses, and essential oils of banana, sweet orange, apple, and pineapple [4]. Previously, insecticides were mixed with attractive food, such as honey, sugar, banana, beer, bread, cornmeal flour, potato, and peanut butter, that were used for the preparation of various baits formulation with the concept that cockroaches like to eat that food [66].

B. germanica preferred 1:3 protein-carbohydrate ratio food and self-selected optimal diets based upon their nutritional needs [69]. Ko et al. [15] determined that baits were the most effective when they matched the intake target and were preceded by food that departed from the intake target. When cockroaches were fed high-quality food and offered bait, they found the bait to be ineffective. It was determined that female German cockroaches compensated for their low dietary protein levels by increasing their consumption rates [55].

B. germanica had hygroreceptors in their antennae for detecting water vapor; however, the antennae were not capable of detecting odors or water vapor over more than a few centimeters [70]. German cockroaches are captured in different places depending on the availability of food or bait [71]. Rust et al. [13] did experiment by using sex pheromones to food-based odorants in German cockroaches. They determined that the direction to attractive baits was directed by olfaction over some distance using an olfactometer.

Silverman and Bieman [72] determined that the German cockroaches collected in different fields of Florida and South Korea showed avoidance behavior to bait formulation containing glucose, and substitution of glucose with D-fructose and/or a mixture of fructose: glucose in molar ratio ≥ 9:1 stimulated feeding behavior. Pol et al. [73] mentioned that German cockroaches were attracted to beer semiochemicals, ethanol, which was the product of formerly living and active yeast. In the process of production of beer yeast, actively metabolize the sugar in mated barley powder that was attractive to German cockroaches. In the laboratory experiment, they found that three components comprising the dry malt extract, water, and brewer’s yeast strongly attracted the German cockroach. Similarly, the food intake of German and American cockroaches was stimulated by many sugars [74]. The sensilla on the maxillary palps of the American cockroach contained sugar-binding sites. Sugars have been frequently incorporated into insecticide-dosed diets as phagostimulants for cockroaches [75].

Frings [76] identified that in the American cockroach, the tarsi and cerci, lack gustatory receptors. The gustatory organs of cockroaches have both maxillary and labial palps. The maxillary palps play a major role in feeding. Moreover, he determined that American cockroaches responded behaviorally to several salts and acids.

Adler [77] reported that a bait made from the distilled grain was an attraction for the brown-banded cockroach but failed to attract American cockroaches during field experiments. Later Brenner and Patterson [78] tested the feeding preference of four species of cockroaches (American, smoky brown, brown-banded, and Florida wood cockroach) and found that brown-banded cockroach showed significant preference for cat chow and the brown-banded cockroach did not prefer distiller’s grains when a choice was provided with other baits. Female brown-banded cockroaches’ consumption rate was decreased when a 5% protein diet was provided, as compared to either 25% protein or commercial rat food [50].

9. Food stimulants

Phytophagous insects have evolved various mechanisms for detecting and avoiding consumption of certain allelochemicals [79]. Tsuji [80] assayed some fatty acid, their esters, and related alcohol in P. americana, B. germamica, and Phragmatobia fuliginosa and found that starved German cockroaches were attracted to n-caproic, n-caprylic, n-capric, and lauric saturated fatty acid, and oleic acid an unsaturated fatty acid. He further mentioned that the most effective attractants in esters were methyl myristate, ethyl myristate, methyl palmitate, and ethyl palmitate. Furthermore, he found that the saturated normal alcohols with 8 to 14 carbon atoms were also attractive for the American cockroach and oleyl alcohol was attractive to the German cockroach [80]. Moreover, the most effective feeding stimulants were n-caprylic acid and methyl myristate. Oleyl alcohol was the stimulant for German cockroaches only. Similarly, Wileyto and Boush [81] found that German cockroaches responded positively to oleyl alcohol, palmitic acid, fenugreek seed alcohol extract, and elaidic acid methyl ester in two choice olfactometer.

The attraction of German cockroaches to esters was tested, and it was found that hexyl hexanoate and pentanoate are attractive compounds and attractiveness was increased ten times with propyl cyclohexane acetate [82]. Moreover, Silverman and Selbach [19] determined that the glucose-averse strain of B. germanica rejected glucose solutions during brief exposure periods (< 5 min) for 2 days with food deprivation. Karimifar et al. [83] mentioned that 1-hexanol from peanut butter and ethanol and 2, 3-dihydro-3, 5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) from beer, are the key semiochemicals for making the food more attractive to B. germanica. It was determined that German cockroaches have hygroreceptors for detecting water vapor [70]; however, they were not detecting odors or water vapor or odors far from a few centimeters. Thus, the success of baiting appeared when located baits were meets maximum during the food searching period of the German cockroach [71].

Tsuji [74] studied the feeding behavior of three cockroach species to the constituents of rice bran and determined that volatile substances soluble in n-hexane acted as olfactory attractants. The feeding stimulants were methanol and the feeding stimulants were sugars and related compounds. The effects for galactose and mannitol were highly species-specific in B. germanica and P. americana. Jakinovich et al. [84] explained that the American cockroach had behavioral taste responses to sucrose and α-D-methyl-glucosides. In another experiment, Wieczorek [85] found that the sensilla field of the maxillary palps in the American cockroach has 2500 taste hairs. Insoluble α-glucoside was detected in the sensilla field of intact palps and hydrolyzed sugars were effective stimuli.

Sugarman and Jakinovich [86] did research on the behavioral gustatory response of the adult American cockroach and identified that the American cockroach responded positively to L-amino acids but not to most D-amino acids. Poultry liver, silkworm pupae, and hydrogenated soy protein were used as protein sources in bait matrices as feeding stimulants [87]. Tsuji [74] determined that attractiveness alone could not effective, it is more effective if it has both attractiveness and feeding stimulants as well which was found in n-hexane the soluble fraction of rice bran.

Moreover, it was found that certain attractants and feeding stimulants are species-specific and a mixture of these substances may have a synergistic effect [74, 80, 88]. Furthermore, [80] found that several fatty acids and related compounds were both attractive and served as feeding stimulants in B. germanica, P. americana, and P. fuliginosa. A mixture of glucose and fructose stimulated a higher feeding rate and a greater response of sugar gustatory receptor neurons in wild-type B. germanica than either fructose or glucose alone [88].

Nojima et al. [89] determined that the eighth tergal gland of male German cockroach secrets methanolic during sequential courtship behavior that contains seven compounds, including oligosaccharides mixture and maltose, maltotriose, and maltotetraose, that strongly stimulated the feeding response of females. Likewise, and an artificial blend of the sugar components significantly increased the polar lipid fraction in the gland and increased feeding stimulants in female cockroaches. Cohen et al. [45] and Ko et al. [15] also reported that higher protein, carbohydrate ratios could attract more German cockroaches. Furthermore, Ko et al. [15] used casein, peptone, and albumin as protein sources in their baits, which were more attractive to German cockroaches. Cohen et al. [45] used casein as the protein and determined that B. germanica and S. longipalpa preferred a higher ratio of casein to carbohydrates. Prakash et al. [90] identified that at 0.5 mg/cm² N, N-diethylphenyl acetamide exhibited residual repellency for 4, 3, and 2 weeks against American, German, and brown-banded cockroaches, respectively.

10. Baits

Ross [91] mentioned that the substance in the formation of bait has the most important role to determine attractiveness, whereas the inactive ingredient has a key role to determine the behavioral response in German cockroaches. For nymph 1–nymph 3 of the German cockroach, bred was found significantly more attractive than goliath gel, however, both were equally attractive for nymph 6 and adult females [17]. They further mention that there were no changes in the level of attractiveness of goliath gel bait either adding or removing fipronil in goliath gel baits. Therefore, several food types, mainly containing three macronutrients (carbohydrate, lipid, and protein) have been used in the food matrices of cockroach baits [92]. The feeding stimulant activity of fructose was less effective than glucose, sucrose, and maltose [20].

Durier and Rivault [17, 93] revealed that fipronil gel was more attractive than boric acid baits. Nalyanya et al. [16] mentioned that avert powder (abamectin), maxforce station and gel, and siege gel (all hydramethylnon) were regularly attractive to German cockroaches and brown-banded cockroach adults and nymphs in trapping experiments. Kaakeh et al. [94] stated that American cockroaches were more attracted to fipronil than combat bait matrix or to other alternative foods. Later, it was determined that German cockroaches frequently choose goliath gel bait (0.05% fipronil) in comparison to avert (0.05% abamectin), maxforce (2.15% hydramethylnon), and drax (33.3% boric acid) gel, and goliath gel induced more feeding stimulant than avert gels [17]. German cockroaches were effectively attracted to noviflumuron and fipronil baits; however, consumption was significantly higher in noviflumuron bait than fipronil baits under laboratory conditions [11].

Anaclerio and Molinari [95] investigated the attraction behavior of four synanthropic cockroach species of B. germanica, S. longipalpa, Blatta orientalis, and P. americana. Cockroach methanol fecal extracts showed a higher intraspecific attraction than aqueous extracts in olfactometer bioassays. They further mentioned that the new gel containing cockroach fecal extracts was more attractive than commercial gel formulations.

It was reported that German cockroaches were attractive and susceptible to fipronil and imidacloprid gel baits. At field levels, the German cockroach population was killed by 100% at 60 days after treatment with 0.05% fipronil and 2.15% imidacloprid gel baits [14, 96, 97].

11. Conclusions and future recommendations

This chapter describes the food detection and feeding behavior of three species of cockroaches (German, American, and brown-banded). The discussion was done on the sensitivity of the compound eyes of these species, specific food preferences of these species, as well as the efficacy of various baits in controlling these species.

It was found that the German cockroaches exhibited a bimodal activity response when they were exposed to natural light conditions, and the activity began at sunset and reached a peak several hours after the onset of darkness. Moreover, it was also found that a second peak activity occurred shortly before the light period began and was more noticeable under natural light than under artificial light. American cockroaches had diurnal locomotory activity correlated with alternating light and dark period; however, there was no correlation between temperature and humidity fluctuation. The brown-banded cockroach, calling occurred discontinuously and followed a diel pattern primarily during the scotophase, in a 12 L:12 h D photoperiod and after transfer to continuous light or dark conditions.

The German cockroach can balance the micronutrient intake by selecting a mixed diet from foods. American cockroaches were able to associate food odors with proteins. Moreover, it was determined that this species exhibited a spontaneous initial preference for vanilla over menthol. Likewise, brown-banded cockroach self-selected a 15.5:84.5 protein: carbohydrate diet.

The German cockroach males foraged for food or water at least once in 7 days out of 10 days, whereas gravid females foraged actively on fewer than 3 days. With their fat and water reserves, female German cockroaches are well-suited to survive without food on a temporary basis. The possession of specific hygroreceptors could play an important role in the food searching behavior of the American cockroach. In the absence of drinking water, the nymphs of brown-banded cockroaches survived significantly longer than German cockroach nymphs.

Cockroach feeding was affected by sex, age, and reproductive condition. The feeding behaviors of female B. germanica differed from nymph and adult males. When resources were farther away from the shelter the number of drinking and eating bouts increased. It was higher and took longer than at lower German cockroach population densities. Male German cockroaches were more active and explored more than females. Feeding and drinking activity peaked during the egg maturation period and ended sharply at the appearance of egg capsules.

German cockroaches had the color vision and the dorsal part of the compound eye had two peak sensitivities. The main visual wavelength spectrum was in the blue-green portion of the spectrum (490 nm), while the minor one was in the ultraviolet. The compound eyes of P. americana contained at least two kinds of receptors. They were stimulated by the blue-green and violet (or ultraviolet) regions of the spectrum. The dark-adapted American cockroach ocellus was dependent on the intensity, but not on the wavelength of stimulating light.

Water was required more critically than food for German cockroaches. Male B. germanica could not survive more than 9–10 days, but females could survive with access to water and without food for up to 45 days.

Food also played an important role in the temporal and spatial distribution of population densities of the German cockroach. German cockroach baits are a mixture of odor or pheromone lures that attract the insect. Two percent Dipterex bait and powdered sugar showed the greatest attractiveness toward German cockroaches. Dextrin and corn starch alone or in combination were the most attractive to nymphs of American cockroaches in laboratory condition. The food intake of German and American cockroaches was stimulated by many sugars. Bait made from the distilled grain was attractive for the brown-banded cockroach but failed to attract American cockroaches during field experiments.

B. germanica had hygroreceptors in their antennae for detecting water vapor; however, the antennae were not capable of detecting odors or water vapor over more than a few centimeters. The sensilla on the maxillary palps of the American cockroach contained sugar-binding sites. It was found that starved German cockroaches were attracted to n-caproic, n-caprylic, n-capric, and lauric saturated fatty acid, and oleic acid an unsaturated fatty acid. He further mentioned that the most effective attractants in esters were methyl myristate, ethyl myristate, methyl palmitate, and ethyl palmitate. Furthermore, it was found that the saturated normal alcohols with 8 to 14 carbon atoms were also attractive for the American cockroach and oleyl alcohol was attractive to the German cockroach. The effects of galactose and mannitol were highly species-specific in the German and American cockroaches. The several fatty acids and related compounds were both attractive and served as feeding stimulants in German and American cockroaches.

Avert powder (abamectin), maxforce station and gel, and siege gel (all hydramethylnon) were regularly attractive to German cockroach and brown-banded cockroach adults and nymphs in the trapping experiment. American cockroaches were more attracted to fipronil than combat bait matrix.

For the control of cockroaches and developing modern baits, specific knowledge on circadian rhythm, food searching behavior, eating, and drinking preferences, effect of population density on feeding and drinking behavior, factors affecting foraging and feeding behavior, visual sensitivity, food attractants, and stimulants should be considered. It is clear that very limited studies were carried out on the sensitivity of the compound eyes and food detection ability and the feeding behavior of brown-banded cockroaches. Thus, further research is needed in those areas for the control of brown-banded cockroaches.