Arthropod Natural Enemies of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in India

Helicoverpa armigera Hubner Lepidoptera: Noctuidae is one of the most serious insect pests in the Old World. In India, it causes substantial losses to legume, fibre, cereal oilseed and vegetable crops. This paper reviews the literature on the biology, ecology, efficacy, rearing and augmentation of endemic parasitoids and predators, as well as exotic parasitoids introduced and released in India. It also provides updated lists of H. armigera natural enemies native to India. In addition, reports of augmentative releases of Trichogramma spp., the most extensively studied natural enemy of H. armigera are summarized

Physical And Chemical Basis Of Resistance To Insects In Wild Pigeonpea

Plgconpca, Cnjnnus cnjan (L.) Millspaugh, an imponant sowce )of high-quailly dictary prolein in the semiarid tropics (Re& el al.. 1981) is altacked by more than 2W species of inxcr ;xsu (Lalcef and Rccd, 1990) which cause yield losses up lo US$ 420 million (ICRISAT. 1992). Helicoverpa armigera is onc of lhc major primary yicid conslrainrs (Latsf and Pimbcn. 1991) besides Marucn icstulnlis, Mclonagromyza obrusq and CIavigraIla spp. So fu. PO..............

Tanaostigmodes cajaninae Promotes Pod Growth in Pigeonpea

Different observations on the effect of T. cajaninae infestation on pigeon pea pod development are briefly discussed

Biology and field performance of Gryon clavigrallae (Hymenoptera: Scelionidae), an egg parasitoid of Clavigralla spp. (Hemiptera: Coreidae) in India

The biology and impact of Gryon clavigrallae Mineo, an egg parasitoid of Clavigralla scutellaris Spinola and C. gibbosa (Westwood), was investigated. The calculated developmental threshold temperatures for females and males were 15.6°C and 15.8°C, respectively. Emergence exceeded 94% at temperatures between 22 and 30°C. Adult females lived on average 28-96 days when fed with honey. Without food, adults lived <6 days. Mean fecundity was 56.4 eggs per female. A significant trend of lower fecundity after longer periods of host deprivation was observed. Gryon clavigrallae females successfully oviposited in host eggs of all ages though eggs <4 days old were preferred. Total host handling times were significantly longer on C. gibbosa eggs (23.5 min.) than on C. scutellaris eggs (12.0 min.). Females readily distinguished parasitized from non-parasitized host eggs. Superparasitism was observed when few or no unparasitized eggs were available. Eggs of the two Clavigralla species can be separated by surface structure and condition after eclosion. Clavigralla scutellaris laid significantly larger egg clusters than C. gibbosa (19.9 versus 10.5 eggs per cluster). Gryon clavigrallae was present as soon as the first Clavigralla spp. egg clusters were found on pigeonpea. The percentage of egg clusters parasitized increased early in the season with egg cluster density and remained high (up to 83%) despite fluctuations in host density. Overall, G. clavigrallae parasitized 40 and 58% of C. gibbosa and C. scutellaris eggs. The percentage of egg clusters parasitized and the number of eggs parasitized per cluster increased significantly with egg cluster size. The overall parasitoid sex ratio was highly female biased but varied with the number of eggs parasitized per cluste

Identification and Management of Pigeonpea and Chickpea Insect Pests in Asia

Pigeonpea (Cajanus cajan (L.) Millspaugh) and chickpea (Cicer arietinum L.) are important grain legumes in Asia. These crops are often heavily damaged by insect pests. Farmers in many areas apply insecticides in an attempt to manage these pests. This bulletin provides descriptions of the most common species, their biology, distribution, and damage symptoms. Color photographs are provided for easy identification. Possible modes of control are also included with an emphasis on integrated pest management and reduced reliance on insecticides

A Braconidae Parasite (Bracon sp. near celer Szepligeti) on Pigeonpea Pod Fly (Melanagromyza chalcosoma Spencer) in Farmers' Fields in Southern and Eastern Africa

The incidence and distribution of Bracon sp. near B. celer, a parasitoid of Melanagromyza chalcosoma, were assessed in major pigeon pea-growing areas in Kenya, Malawi, Tanzania and Uganda, during 1995 and 1996. Populations of M. chalcosoma were greatest in Kenya and infestations were high in areas where the crop matured late in the season or in cool weather. Areas near the coast at <500 m altitude had insignificant populations of M. chalcosoma and no parasitoids were recorded. As the pest population increased, the incidence of the parasitoid also increased. Mean parasitism rates were recorded as 5.2, 2.6, 3.0 and 2.3% for Kenya, Malawi, Tanzania and Uganda, respectively.It is concluded that B. celer is widespread and could contribute to the management of M. chalcosoma on pigeon peas

Insect pests of pigeonpea and their management

Pigeonpea (Cajanus cajan) is an important crop in semi-arid tropical and subtropical farming systems, providing high quality vegetable protein, animal feed, and firewood. Insect pests feeding on flowers, pods, and seeds are the most important biotic constraint affecting pigeonpea yields. This review summarizes the biology and ecology of the three most important groups of pests: flower- and pod-feeding Lepidoptera, pod-sucking Hemiptera, and seed-feeding Diptera and Hymenoptera. Recent research investigating the complex interactions among pigeonpea, its key pests, and their natural enemies is also reviewed. These relationships have implications on the pest status of individual species and on possible control strategies. Pigeonpea pest management research has focused until recently on the identification and development of resistant cultivars and on chemical control. Future research must focus on environmentally sound pest management strategies that are compatible with the needs and limitations of pigeonpea farmers. Several priority areas for research are suggested

Biology and control of the groundnut leafminer, Aproaerema modicella (Deventer) (Lepidoptera: Gelechiidae)

The groundnut leafminer, Aproaerema modicella (Deventer) (Lepidoptera: Gelechiidae), is an important pest of several legume crops in South and South-East Asia. For groundnut, yield losses of >50% have been reported. In addition to groundnut and soybean (the main crops attacked), 12 alternative host plants have been reported. A. modicella is present throughout the region, although it has been studied most intensively in India and Thailand. Research conducted over the past 10 years has provided a good understanding of the biology, life cycle and natural enemies of this pest. Research on management has focused on chemical control. This paper reviews the literature on the host plants, distribution, biology and control of A. modicella, emphasizing research reported since 1980. Aspects of A. modicella ecology that need further study are also indicated