Population Dynamics of the Rubber Plantation Litter BeetleLuprops tristis, in Relation to Annual Cycle of Foliage Phenology of Its Host, the Para Rubber Tree,Hevea brasiliensis

Abstract

The population dynamics of the rubber plantation litter beetle, Luprops tristis Fabricius 1801 (Coleoptera: Tenebrionidae) was assessed in relation to the phenology of leaf shedding and defoliation pattern of para rubber trees, Hevea brasiliensis Müll. Arg (Malpighiales: Euphorbiaceae), during a two year study period. The abundance of adults, larvae and pupae per 1m2 of litter sample was recorded. Post dormancy beetles appeared in leaf litter following annual leaf shedding, whereas larvae, pupae and teneral adults were present after leaf flush. No stages were recorded from plantations following the summer rains until the annual litter fall in the next season. Parental adults peaked at the time of leaf sprouting and tender leaf fall. Larvae and teneral adults peaked at the time of premature fall of green leaves and flowers. Teneral adults of six age classes were recorded and all entered dormancy irrespective of the feeding time available to each age class. Females outnumbered males in the parent generation, while the sex ratio of new generation adults was not biased towards either sex. The phenological stages of rubber trees included leaf fall in late December and early January, leaf sprouting and new leaf production in January and flowering in February. All feeding stages of L. tristis peaked in abundance when premature leaves are most abundant in the leaf litter. Prediction of the timing of appearance of various developmental stages of L. tristis in plantations, invasion into buildings and intensity of population build up in rubber belts is possible by tracking the phenology of leaf fall in rubber plantations, time of return of post dormancy adults and the onset of summer rainfall. Perfect synchrony was recorded between the field return of parental adults with annual leaf shedding, the oviposition phase of parental adults with tender leaf fall at the time of leaf sprouting, and larval and teneral adult stages with premature fall of leaves. Premature leaf availability is suggested as contributing to the reproductive efficiency of parental adults, the survival of early developmental stages and of new generation adults during dormancy.

Effects of plant latex based anti-termite formulations on Indian white termite <i>Odontotermes obesus</i> (Isoptera: Odontotermitidae) in sub-tropical high infestation areas

“…These have protected the wood weight loss up to 3.94% and no infestation was observed even after 6 months of experiments ( Table 4). All such insecticidal actions of latex are due to presence of different bio-chemicals of diverse biological activity [5]. Similarly, natural amides such as nootkatone [70], valencenoid derivatives [71], imidacloprid [72] deter feeding in termites and suppress adult survival [73].…”

“…Plant latex is a complex mixture of proteins, alkaloids, starch, sugars, oils, tannins, resins, and gums [5]. It is a natural plant polymer secreted by highly specialized cells known as laticifers [6].…”

Valorisation of Proteins from Rubber Tree

“…The tree can be leafless for 2-4 weeks, after which refoliation occurs during 1 month (Fig. 7) [17,57,58]. The amount of leaves varies between clones, age, and time of the year.…”

Host Plant and Leaf-Age Preference ofLuprops tristis(Coleoptera: Tenebrionidae: Lagriinae: Lupropini): A Home Invading Nuisance Pest in Rubber Plantation Belts

“…Arg. 1865] are the breeding and feeding habitat for L. tristis, with prematurely abscised leaves as the most preferred food resource, and a synchronized life cycle with the leaf phenology of rubber [2]. Their near absence in natural forests in contrast to exceptionally high abundance in rubber plantation litter established that rubber is the major host plant of the insect in the region [3][4][5].…”

“…Their near absence in natural forests in contrast to exceptionally high abundance in rubber plantation litter established that rubber is the major host plant of the insect in the region [3][4][5]. Prevention of premature leaf fall of rubber may regulate the population build up of L. tristis in rubber plantations [2,5]. However, their presence in the leaf litter of trees namely, cashew (Anacardium occidentale, Linnaeus 1753), mango (Mangifera indica, Linnaeus 1753), jackfruit (Artocarpus heterophyllus, Lamarck 1789), wild jack (Artocarpus hirsutus, Lamarck 1789), cocoa (Theobroma cacao, Linnaeus 1753), cassia (Cassia fistula, Linnaeus 1753), and sapota (Manilkara zapota, Linnaeus 1753) co-occurring in rubber belts (personal observations, first author) led to the hypothesis that L. tristis may also feed on the leaf litter of these plants.…”