126 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XVI- 



Fig. 44. — Cotesia flavipes, which is parasitic upon 

 the well-known destructive sugarcane 

 borer Chilo simplex. (Bengal.) Antenna 

 enlarged on the right. 



Cotesia flavipes, shown in fig. 44, is a tiny fly which lays its eggs in 



the caterpillars of the 

 destructive sugarcane, 

 borer Chilo simplex (a 

 moth which will be treat- 

 ed of later) and serves to 

 keep the numbers of this 

 destructive pest in check, 

 since the chalcid grubs feed 

 upon and kill off the 

 caterpillars. In a similar 

 manner Chalcis euplcea 



shown in fig. 45, very effectively keeps down the numbers of some very 



important tea and sal tree defoliating 



caterpillars (Lymantria and Dasychira) in 



the Bengal Duars and Assam. At times 



these caterpillars get the upper band and 



swarm in incredible numbers, clearing 



every leaf from the bashes and trees. 



This leads after a few weeks to a similar in- 

 crease in the numbers of the chalcid, which 



finally succeeds in bringing down to due 



J i Fig. 45 



proportions the numbers of the moth cater- 

 pillars. The family Coccidae or scale Insects 

 (Order Hemiptera) contains many serious 

 pasts both to crops and planters. Observation has shown that many 



of these are parasitised by 

 ■"%», iljp /^ ^-~°~\ chalcid fiios. The eggs are 



laid as usual by the female 

 chalcid in the body of the 

 scale Insect, and the grubs on 

 hatching out feed upon and 

 destroy the scale. Amongst 



chalcids which are known 

 Fig. 4f5. — Aphelinus tliece, which is narasitic upon 



the tea scale bug. True size of insect is t0 be of use in this wa y ma Y 



Blightly less than -5 millim. (India.) be mentioned Aphelinus thece 



(shown in fig. 4G) parasitic on the tea scale bug (Chionaspis thece), 



Cirrhospilus coccivorus, Encyrtus nietneri, E. paradisicus, Scutellista 



Chalets tuplcea parasitic 

 upon tea and sal leaf 

 defoliating caterpil- 

 lars. (Bengal Duars.') 



