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Population Dynamics And Parasitism Of Brassica Insect Pests In Zimbabwe With Emphasis On The Diamondback Moth, Plutella Xylostella (L.) (Lepidoptera: Plutellidae), Walter Manyangarirwa
Population Dynamics And Parasitism Of Brassica Insect Pests In Zimbabwe With Emphasis On The Diamondback Moth, Plutella Xylostella (L.) (Lepidoptera: Plutellidae), Walter Manyangarirwa
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The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a major insect pest of brassicas in Zimbabwe. Field surveys were conducted to assess brassica pest management practices at large scale farms (≈2.0-10.0 ha) and smallholder farms (<2.0 ha). Insecticides used on large scale farms include λ-cyhalothrin, fenvalerate, dimethoate, malathion, diazinon, dichlorvos, kelthane and lufenuron. Smallholder farmers predominantly used dimethoate, malathion, diazinon, methamidophos, dichlorvos, fenvalerate, carbaryl and methomyl. Six out of seven smallholder farmer clusters were ranked into an Intermediate Category between Integrated Pest Management (IPM) practices and Conventional Insecticide use. Smallholder farmers in the Chinamhora area were ranked into a Conventional Insecticide use category. Five out of seven large scale farms were ranked into a Conventional Insecticide use category while two of the seven farms were ranked into an Intermediate Category.
Diamondback moth larval incidence was high in the hot-dry season in October and November of both 2007 and 2008 and reached a density of 15.58 larvae per plant at Nyanga in November 2008. The major larval endoparasitoid was Cotesia plutellae (Hymenoptera: Braconidae) and parasitism reached 95.51% at a host density of 2.83 larvae per plant at Harem in early summer (October and November) …
Comparative Morphological And Functional Analysis Of Wing Coupling And Related Structures In Caddisflies (Insecta: Trichoptera), Ian Stocks
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Several orders of morphologically four-winged insects have evolved mechanisms that enforce a union between the mesothoracic and metathoracic wings (forewings and hindwings) during the wing beat cycle. Such mechanisms result in a morphologically tetrapterous insect flying as if it were functionally dipterous, and these mechanisms have been described for several insect orders. The caddisfly suborders Annulipalpia and Integripalpia (Trichoptera) have each evolved wing coupling apparati. At least three systems have evolved within the suborder Annulipalpia (Polycentropodidae; Hydropsychidae: Hydropsychinae, Macronematinae), and within Integripalpia the evolution of wing coupling mechanisms is diverse to the point that it defies simple enumeration into discrete …
The Ants Of South Carolina, Timothy Davis
The Ants Of South Carolina, Timothy Davis
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The ants of South Carolina were surveyed in the literature, museum, and field collections using pitfall traps. M. R. Smith was the last to survey ants in South Carolina on a statewide basis and published his list in 1934. VanPelt and Gentry conducted a survey of ants at the Savanna River Plant in the 1970's. This is the first update on the ants of South Carolina since that time.
A preliminary list of ants known to occur in South Carolina has been compiled. Ants were recently sampled on a statewide basis using pitfall traps. Two hundred and forty-three (243) transects …