The vegetables belonging to family cucurbitaceae are known as cucurbits. These vegetables are attacked by various insect pests right from seeding to harvest. A lot of money, time, and natural resources are invested to cultivate these vegetables. Sustainable pest management practices can save this investment by avoiding losses. Successful cultivation of cucurbits especially cucumber requires an effective and economical control of insect pests. Commercial vegetable growers must produce quality vegetables that are attractive and safe to the consumer at a minimum cost. Insect pest infestations in cucurbits cause heavy economic losses to farmers through reduction in yield, increased cost of production and lowered quality of produce. Effective and economic and sustainable pest management requires the use of cultural, mechanical, biological, and chemical methods. The integration of these different methods is necessary for achieving good management of pests. In case of cucurbits especially for cucumber pest management can be achieved only by a long-term assurance to integrated pest management practices (IPM). IPM involves the strategic use of resistant varieties, monitoring of pest incidence, cultural methods, mechanical removal of pest, biological control, and need based use of selective pesticides. Integrated pest management (IPM) is the alternative to insecticide and facilitates sustainable environment management.
- Pest Management
- Insect Pests
Crops belonging to the family Cucurbitaceae are commonly called cucurbits, which include more than 120 genera and 1000 species distributed in tropical and subtropical areas. Cucurbits are tropical in origin and grown mostly in Africa, tropical America, and Asia, mainly Southeast Asia. Cucurbits are a large group that include cucumber, bitter gourd, squash, bottle gourd, ridge gourd, snake gourd, watermelon, muskmelon and pumpkin. Most of the gourds and squashes are commonly used for cooking while cucumber is used for salads and pickles. Watermelon and muskmelon are taken as fruits and wax gourd is prepared as biscuits and jam. The cucurbits are beneficial for human health as their fruits help in purification of blood, boost energy level, improve digestion in the body and remove constipation.
Most cucurbit species is believed to have an African origin. However, cucumber have originated from the foothills of the Himalayas. There the closely related wild species
In present scenario, a significant constraint in the sustainable production and productivity of cucurbits is mainly due to attack of various insect-pests which are responsible for adversely affecting the qualitative and qualitative yield. A wide range of pest complex has been noticed infesting the cucurbits. This chapter joins all the information and provide overall review about the major insect pest of cucumber and other cucurbits, and different IPM measures like monitoring, cultural methods, host resistance, biological control method, use of botanicals as biopesticide and at last use of less hazardous chemical control methods recommended for management of this pest.
1.1 Melon fruit fly
, Bactrocera cucurbitae(coquillett)
Cucurbits fruits are picked up at small intervals for marketing and self-consumption for that reason we cannot rely on insecticide for control of this pest but under severe infestation, it is important to use low residual toxic insecticides with short waiting periods. Therefore in keeping view the importance of crop and this pest different strategy should be used for the management of fruit fly as follows.
184.108.40.206 Local area management
Local area management is the minimum scale of pest management over a restricted area l, which has no natural protection against reinvasion. Here the major objective is to suppress the pest, rather than to eradicate it. The strategies includes bagging of fruits, field sanitation, protein baits and cue-lure traps, host plant resistance, biological control, and soft insecticides, can be employed to avoid environmental and health hazard .
220.127.116.11 Monitoring and management with cue/pheromone lures
For the monitoring of fruit flies, the sex attractant cue-lure traps are more effective than the food attractant tephritlure traps. and cue-lure and methyl eugenol traps have been used to attract males for monitoring and mass trapping [5, 6].
18.104.22.168 Cultural methods
Field sanitation is most effective method in melon fruit fly management. It should be done for minimising pest intensity and to break reproduction cycle by removal and destruction of infested fruits daily from the field and bury the damaged fruits 0.46 m deep into the soil . Akhtaruzzaman et al.  recommended bagging of cucumber fruits after 3 days of anthesis and bag should be kept for 5 days for effective control. Bagging of 3–4 cm long fruits with two layers of paper bags reduces fruit fly infestation and enhances the net returns by 40–58% . 2–3 rows of maize as a trap crop can be grown between the cucurbits, which can be used as a resting site by the adult fruit fly. Spraying of any contact insecticides can be done on maize during the evening hours to kill adult fruit flies.
22.214.171.124 Biological control
Srinivasan  reported
126.96.36.199 Host plant resistance
Host plant resistance is an important element in IPM programs It is an important component in IPM programs. It does not cause any negative impact to the environment. The success in developing high yielding and melon fruit fly-resistant varieties is limited. By using wide hybridization technique the resistance genes from the wild relatives can be transferred in the cultivated genotypes of cucurbits . Some resistant genotypes are IHR 89, Hisar II for bitter gourd, Arka Suryamukhi, IHR 35 for pumpkin, NB29 and Pusa smooth purple long for bottle gourd, Arka Tinda for round melon,
The adult longevity reduced from 119.2 to 26.6 days by continuous feeding with extract of
188.8.131.52 Chemical control
The use of chemical insecticide to manage fruit fly is relatively ineffective. Application of malathion (0.05%) as cover spray to kill the insects on contact is effective or a bait spray by adding 50 g gur + 10 mL malathion in 10 L water that attract and kill the adults is good for its management. For good control of fruit fly spraying of malathion + molasses + water in the ratio of 1:0.1:100 is suggested by Akhtaruzzaman et al. . This method is economical and environmental friendly as there is very low contamination of fruits from insecticides. Gupta and Verma  recommended that fenitrothion (0.025%) in combination with protein hydrolysate (0.25%) minimised melon fruit fly infestation to 8.7% compared to 43.3% damage in untreated control. Reddy  reported that triazophos is the most effective insecticide to manage this pest on bitter gourd. Diflubenzuron is also found effective in controlling the melon fruit fly , and quinalphos (0.2%) successfully manage its population on different cucurbits.
1.1.2 Wide area management
The objective of wide area management is to combine and coordinate different characteristics of an insect eradication program over an entire area within a defensible perimeter. This management program includes a three-tier model, that is, early reduction in population using bait spray, inhibition of reproduction using para-pheromone lure blocks to eradicate males to avert oviposition by females, and intensive survey using traps and fruit inspection until it could be discovered that the pest is entirely eradicated . Male-sterile technique, also incorporated under this program, in this sterile males are released in the fields for mating with the wild females. The transmission of dominant lethal mutations kills the progeny of fruit fly. The females either do not lay eggs or lay sterile eggs. Eventually, the pest population can be eradicated by maintaining a barrier of sterile flies . The spread of the melon fruit fly can be blocked through tight quarantine and treatment of fruits at the import/export ports.
1.2 Red pumpkin beetle (
Raphidopalpa foveicollis/ Aulacophora foveicollis)
Red pumpkin beetle is a common and major pest of a wide range of cucurbits, especially sweet gourd, bitter gourd, watermelon, bottle gourd, and muskmelon. It is polyphagous in nature . Both larval and adult stages are voracious feeders of the cucurbit crops and cause severe damage to seedlings and young and tender leaves and flowers [26, 27]. The pest is widely distributed in different parts of the world, especially in Asia, Africa, Australia, and south Europe. In India, it occurs throughout the country but is more common in the north western parts.
The dorsal body of the adult beetle is deep orange in colour, while the ventral side is black. The beetles are about t 5–8 mm in length and 3.5–3.75 mm in width. The posterior part of the abdomen bears soft white hairs. The female lays brown coloured elongated eggs in the moist soil in the clusters of 8–9 that hatch into larvae in 6–15 days. After about 7 days of emergence, beetles starts egg laying and complete its 5 generations from March to October. Larvae are creamy, yellow-coloured and feed on the roots, stems, and fruits touching the ground. Due to infection by the saprophytic fungi rotting of damaged roots and underground stems may be occurred. Leaf lamina of cucurbits is voraciously feed by scrapping off the chlorophyll and making irregular holes on leaves with netlike appearance by beetle. First generation is more injurious than the subsequent generations as the maximum damage is noticed during cotyledon stage. The infested plants may shrivel, and resowing/replanting may become important under severe infestation. The young and smaller fruits of the infested plants may dry up. Sweet gourd was the most susceptible while bitter gourd was found to be the least susceptible host for this pest . Beetles are strong fliers and very active in hot weather, and when disturbed, take fly quickly. If it is not controlled timely the damage by this pest may become severe. The losses due to the pest have been reported up to 30–100% in the field conditions .
184.108.40.206 Monitoring and cultural methods
Monitoring of seedling should be done twice a week to check the infestation of red pumpkin beetle. The older plant parts should be monitored regularly and should be treated if severe defoliation is noticed. In the initial stage of infestation collection and destruction of beetles is good practice, otherwise the alternative practices can be employed for the management of this pest. Preventive measures such as burning of old plant parts, ploughing, and harrowing of field after harvesting of the crops should be followed for the destruction of all the stages of this pest. Early planting of cucurbits than the normal planting time could also be effective in management as the plants pass the cotyledonary stage by the time the beetles become active.
220.127.116.11 Host plant resistance
Khan  reported the preferred cucurbit host plants for this beetles and categorised bitter gourd, ribbed gourd, sponge gourd, and snake gourd as non-preferred hosts (resistant), while cucumber, muskmelon, and sweet gourd were the most preferred hosts (susceptible) and bottle gourd and ash gourd were moderately preferred hosts (moderately susceptible).
18.104.22.168 Botanicals and biopesticides
Application of neem oil cake in the soil is effective in killing grubs. Treatment of bottle gourd plants with entomopathogenic fungi
22.214.171.124 Chemical control
Generally, this pest attacks the crop at the cotyledonary stage when adults skeletonize the young leaves. At the time of initial infestation, applications of malathion (0.5%) or carbaryl (0.1%) minimise the damage successfully . Dusting with permethrin (0.5%) alone and ash + permethrin dust (2000:1
1.3 Hadda beetle (
Epilachna implicate, E. viginitioctopunctata and E. borealis)
This is an occasional pest on cucurbit. It is a serious pest of squash, bitter gourd, and pumpkin. Grub only feed on the underside of the leaf, whereas adults may be found to feed on both the leaf surfaces or even on the fruit rind, leaving spiral-shaped scars and deteriorating fruit quality . Both grub and adult feed voraciously by scrapping the chlorophyll of the leaves which cause characteristic skeletonization of leaf lamina and leaving a fine net of veins on leaves. The affected leaves gradually dry and fallen down. The young plants are killed overnight in case of severe infestation. The yellowish-brown coloured adult beetles are globular in shaped and 6–8 mm long, bearing 12–28 black spots on the elytra. The female lays about 300–400 eggs in clusters on the under surface of the leaves. Eggs on hatching turns into yellowish larvae (grub) with branched black spines covering the body. Full-grown larvae about 7-9 cm long pupate below the leaf or at the base of the stems. The pupa is yellow in colour, and lacks spines and hangs from the leaf. The development period comprises of 4–6 weeks under optimal conditions. Adults make semicircular cuts in rows, while Scrapping of the epidermis indicates the feeding manner of the grubs. Young plants can be totally destroyed, but older plants can tolerate considerable leaf damage. Overwintering sites for adults are under loose tree bark or under leaf litter near the edge of fields.
126.96.36.199 Cultural methods
The best time of day for the inspection of hadda beetles on cucurbits is around noon. As they are not strong fliers, so crop rotation to distant fields tends to limit population and colonisation . On the small scale like kitchen garden handpicking is recommended for the management of this pest because both the larvae and adults are not very aggressive defoliators. Harrowing and destroying vines and larvae after harvesting early cucurbits is recommended to suppress pest population. Row covers can be used to protect cucurbit from the beetles.
The application of seed extracts of
188.8.131.52 Chemical control
Foliar applications of some synthetic pesticides like parathion, malathion, lambda-cyhalothrin, pyrethrin and spinosad are found to be effective in control of severe infestation of this pest.
1.4 Aphid (
Myzus persicae and Aphis gossypii)
Many aphid species including melon aphid (
Aphids multiply at a very fast rate, and this must be considered while monitoring this pest. Plants should be inspected at least two times a week especially at the under surface of the leaves. Severe infestation is noticed during end of growing season. Yellow sticky traps should be used for detecting aphids 2–3 weeks prior to planting.
184.108.40.206 Cultural method
Floating row covers or reflective mulches may be effective to exclude or repel this pest . On early crop stage, aluminium foil mulches can be used to repel the invading aphid and check transmission of viruses. Reflective mulches can increase temperature beyond optimum for cucurbits in very hot and arid regions therefore, not recommended for these areas. Reflective mulches repels aphids from plants and consistently suppress aphid population and also help in delaying symptoms of watermelon mosaic and cucumber mosaic cucumo virus and zucchini yellow mosaic potyviruses by 3–6 weeks. Biodegradable synthetic latex spray mulches and reflective polyethylene and provide good control of aphids and aphid-borne virus diseases on late-season melons . Living mulches minimise the contrast between the plant foliage and bare land, subsequently, the aphids do not detect their host and these mulches around main crop provide additional feeding sites for viruliferous aphids (aphids carrying virus) and hence minimise aphid-borne non -persistently transmitted viruses incidence and spread .
220.127.116.11 Biological control
Beneficial insects like predators, parasitoids, and pathogens are attracted to plants with moderate to heavy aphid infestations. These natural enemies may attack large numbers of aphids but as the reproductive potential of aphids is very high hence, the impact of the these natural enemies may not be enough to keep the aphids population below economic threshold levels. Lady bird beetles and their larvae
18.104.22.168 Chemical control
Potassium soap and petroleum oil or Actara are recommended for the management of this pest. Killing of aphid population should be done before destroying old crops to avoid winged virus-infected aphids from getting to nearby crops by using a detergent and vegetable oil solution. Acetamiprid (0.01%) or Cypermethrin (0.01%) or malathion (0.05%) can be used to control aphids.
1.5 Whitefly (
Bemisia tabaci, B. argentifolii and Trialeurodes vaparariorus)
Cucurbits are attacked by several species of whiteflies. Of these, silverleaf whitefly
For early detection and monitoring the activity of whiteflies in the field, yellow sticky traps can be used. These traps are very important step for their management of whitefly. Traps should be placed just above the canopy at every 100 m2 distance of the crop as whiteflies are most attracted toward young foliage .
22.214.171.124 Cultural methods
Crop rotation, mulching, floating row covers, non-infested transplants, cover crops, and good field sanitation are some common cultural practises to prevent the build-up of whiteflies. Delayed planting or host-free periods may reduces severity of infestation as temperature and rainfall influence whitefly population dynamics [56, 57]. Soil ground covers such as living or synthetic mulches have been found to suppress whitefly infestation [52, 58]. UV-reflective plastic mulch provide good management of silverleaf whitefly by repelling the adults flies, which minimize their colonisation and nymph population on zucchini squash and pumpkin . Field sanitations an important practice to control whiteflies infestation, whitefly-transmitted virus incidence, and insecticide resistance. Crop residues that shelter whiteflies should be destroyed immediately after final harvesting to reduce their population and sources of plant viruses . Weeds should be eradicated regularly from the crop as they can support large populations of whiteflies.
126.96.36.199 Biological control
Natural enemies of whitefly such as
Azadirachtin containing neem-based pesticide formulations like NeemAzal and Azatin have been found to control young nymphs and inhibit growth and development of older nymphs, and suppress egg laying by adult flies. Soap and certain oil sprays can be used in an organically certified crop. The efficacy of neem-based pesticides can be increased by adding 0.1%–0.5% soft soap in it.
188.8.131.52 Chemical control
The adults at immature stage reside on the underside of leaves, therefore whiteflies are usually difficult to control by using chemicals. Neonicotinoid insecticide like imidacloprid or thiamethoxam applied in soil at the time of planting effectively controls whiteflies. Foliar spray with neonicotinoid insecticide such as acetamiprid can be done at early stages of growth before flower initiation. Spiromesifen is effective against immature stages of the whitefly . Consecutive applications of the same insecticide should be avoided. Soil application of any neonicotinoid with a foliar application of another neonicotinoid never be followed.
1.6 Squash bug (
The pest has been reported to attack nearly all cucurbits but most preferred cucurbits for oviposition and high rates of reproduction and survival are squash and pumpkin. It damages the crop severely by secreting highly toxic saliva into the cucurbit. Foliage is the primary site of that wilts, becomes blackened, and dies upon feeding. The fruits are also infested. The intensity of damage is directly proportional to the population density of pest. The adults emit a strong odour when crushed.
184.108.40.206 Cultural methods
Plastic and spun bounded material can be used a row cover at the time of planting. Straw mulch is found effective in controlling squash bugs by providing cover . As this pest prefers squash over other cucurbits, squash planting can be used as a trap crop around other cucurbits. Trap crop squash can be treated with insecticide to control the infestation.
220.127.116.11 Biological control
Several natural enemies are known to parasitize squash bug, especially Hymenoptera parasitoids belonging to family Encyrtidae and Scelionidae. A important tachinid fly parasitoid
Certain plant derived oils such as neem oil are helpful in the management of squash bug.
18.104.22.168 Chemical control
For the successful squash bug control timing of application is the key. Systemic insecticides are effective in suppression of these bugs up to 3 weeks. Foliar sprays targeting newly hatched nymphs are more effective than sprays used against older stages. Multiple foliar sprays are often needed for long periods of control. Soil application of dinotefuran and pyrethrin in foliar application are recommended for management of this pest .
The attacks made by the insect pests in cucurbits cause severe yield and quality losses in cucurbits. Cucurbitaceous crop are an important part of the fresh market vegetable crops. The current pest management still relies mainly on chemical pesticides and excessive dependence on chemicals leads to environmental pollution, pest resurgence, pest resistance and disturbance in balance between pest and their natural enemies. There are also the real and important risks to human health and environment as insecticide residue persist in these vegetables for longer times. Therefore, an integrated approach including monitoring of pests; cultural methods, like field rotation, use of mulches and trap crops and shifting planting dates; resistant cultivars; biological control; botanicals and biopesticides; and judicious use of chemicals can minimise these associated risk with chemical pesticides. An effective integrated programme for pest management is necessary for the management of these pest problems in cucurbits. By giving focused attention through adopting IPM techniques, sustainable production of cucurbits can be achieved.