Effect of Benzoylphenyl Ureas on Survival and Reproduction of the Lace Bug, Leptopharsa gibbicarina

Abstract

The lace bug, Leptopharsa gibbicarina is a vector of Pestalotiopsis fungal complex in oil palm crops in the Americas. The effects of four benzoylphenyl ureas (BPUs) (lufenuron, novaluron, teflubenzuron, and triflumuron) were evaluated against L. gibbicarina for toxicity, survival, reproduction, and mortality in semi-field conditions. Concentration-mortality bioassays demonstrated that novaluron (LC50 = 0.33 ppm), teflubenzuron (LC50 = 0.24 ppm), lufenuron (LC50 = 0.17 ppm), and triflumuron (LC50 = 0.42 ppm) are toxic to L. gibbicarina nymphs. The survival rate was 99% in control nymphs, decreasing to 50% in nymphs exposed to LC50 of triflumuron, 47% in nymphs treated with lufenuron, 43% in nymphs treated with teflubenzuron, and 43% in those treated with novaluron. Sublethal concentrations of BPUs showed detrimental effects on the adult emergence, longevity, fecundity, and fertility of this insect. The mortality of nymphs caused by these insecticides was similar in both laboratory and semi-field conditions. Our results suggest that novaluron, teflubenzuron, and triflumuron are highly effective against L. gibbicarina, and therefore, have potential applications for this oil palm pest.

Effects of Insect Growth Regulators on Mortality, Survival, and Feeding of Euprosterna elaeasa (Lepidoptera: Limacodidae) Larvae

“…Additionally, the findings show that methoxyfenozide and tebufenozide affect a high number of E. elaeasa larvae. It is possible that the efficacy of IGRs under field conditions is due to climatic factors [52], translaminar action [53], chemical degradation [54], and the persistence of biorational insecticides in foliage [17]. However, while it is difficult to accurately determine the quantity of insecticide penetrating (by contact or ingestion) each insect, mortality caused by IGRs on E. elaeasa was similar to that found with topical application in the concentration-mortality bioassay.…”

“…The use of biorational agents is an important tool for the alternative management of oil palm pests [17] and their application was proven to reduce populations [18]. The current suite of biorational insecticides includes chitin synthesis inhibitors, ecdysone receptor agonists, and juvenile hormone mimics, distinguished by physiological activity interfering with the growth and development of insects [19][20][21].…”

“…The current suite of biorational insecticides includes chitin synthesis inhibitors, ecdysone receptor agonists, and juvenile hormone mimics, distinguished by physiological activity interfering with the growth and development of insects [19][20][21]. The effects of these insecticides have been investigated to control oil palm pests such as Eupalamides cyparissias Fabricius (Lepidoptera: Castniidae) in Brazil [22], Leptopharsa gibbicarina Froeschner (Hemiptera: Tingidae) in Colombia [17], and Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) in Malaysia [23]. Insect growth regulators (IGRs) act in insect development and mediate the balance of ecdysone [21] or juvenile hormone [20].…”

Global Advances on Insect Pest Management Research in Oil Palm

“…Euprosterna elaeasa is commonly controlled using synthetic insecticides, although insecticide-resistance has been noted [50]. Essential plant oils, notably from Cymbopogon martinii [51], insect growth regulators such as fenoxycarb, methoxyfenozide, pyriproxyfen, and tebufenozid [52], the nucleopolyhedrosis virus EuelNPV [53], and Bacillus thuringiensis Berliner (Bt) strains [52] have demonstrated toxicity and/or antifeedant activity against E. elaeasa at levels that are comparable or superior to conventional insecticides, under controlled trials, and are recommended for evaluation as components of integrated approaches against the pest in the field [44,53].…”

“…Another notable tingid associated with oil palm is Leptopharsa gibbicarina Froeschner [8]. It is also the main vector of the Pestalotiopsis fungal complex in oil palm in the Americas [52]. The females insert their eggs into leaf tissue along a major vein of the abaxial surface, usually covering them with excrement.…”