Teamosquito bug, Helopeltis theivora Waterhouse (Family: Miridae) is one ofthe most dreaded polyphagous pest.
This pest has emerged as a commonlyoccurring major pest of cashew (Srikumar and Bhat, 2013, Vanitha et al., 2014)and large cardamom plants by sucking the sap from the leaves developing darkbrown streak stains (Kalitha et al., 2016). In tea it causes damage to thetune of 10 -50% followed by subsequent crop loss (Bora et al., 2007).
This pest recently is causing severe economic loss to the North Bengal tea plantationsdue to environmental changes (Mukhopadhyay and Roy 2009). Nymphsand adults both suck the sap from pluckable buds, young leaves and tender stemsand in addition inject toxic substances (Roy et al., 2009 a) whichresults in appearance of reddish brown sunken spots which eventually turns darkcurl up and deform. Severe infestation may cause shoots to produce diebacksymptoms (Roy et al., 2015). Moreover, this pest causes ovipositionaldamages to the tender tissues. It attacks only the young shoots which are theactual crop of tea (Rahman et al.
, 2005). Therefore, cause considerableeconomic losses. Chemicalcontrol would continue to be the first line of defense against this pest.However, control failures due to pesticide resistance have increased thedifficulty in economic tea production (Gurusubramanian et al.
, 2008 andSaha et al., 2013). To combat the damage there has been a rise inpesticide use every passing year which further aggravated the problem and hasled to significant rise in cost of management (Sannigrahi and Talukdar, 2003).Hence, as traditional and cultural practices alone cannot give satisfactorycontrol over the pest menace (Vanlaldiki et al., 2013), small andmarginal farmers are compelled to use chemical insecticides in order tocultivate lucratively. In order to address the aforesaid problems newinsecticides can be thought as alternative and effective new bio-rational andeco-friendly molecules that are safe to natural enemies and non-targetorganisms and also to human health and environment (Chakraborty et al., 2010,Reddy et al.
, 2014).Tea mosquito bug, Helopeltistheivora Water-house (Hemiptera: Miridae) is one of the most serious pestsof tea in Bangladesh. It is also widely distributed in India, Sri Lanka,Viet-nam, Indonesia, Malaysia and Africa. It is also a phytophagous pest ofcoffee, cocoa, cashew etc. A group of genomes are treated as a mosquito bug.This bug bears no relation to mosquito and the name ‘Tea Mosquito Bug’ issimply a misnomer.
It is considered as one of the major pests of Bangladesh teabecause it attacks only to the young shoots that are the actual crop of tea.Ahmed (2) reported that 10-15% of tea crop is lost annually by Helopeltis whichsometimes may go up to 100% crop loss. Both the nymphs and adults damage theplant by sucking sap from young leaves, buds and tender stems. Due to intensivefeeding by nymphs and adults, leaves curl up and are badly deformed. Inaddition to direct crop loss, damage by Helopeltis leads todebilita-tion of bushes resulting in die-back with crows-feet and delayed ormeager flushing thereafter consequently almost the entire crop is lost.
Mamun(6) described that many differ-ent tactics are used in IPM strategy for teamosquito bug in tea plantation, including cul-tural practices, biologicalcontrol agents, pest-resistant varieties, physical barriers and chemicalpesticides etc.