Insect Control: Biological and Synthetic Agents - Index of

Table 2 Biological activity of spinosyns towards selected insect and mite species
Number Compound
6: The Spinosyns: Chemistry, Biochemistry, Mode of Action, and Resistance 211
Heliothis
virescens,
neonate
(LC50, ppm)
Calliphora
vicina,
larvae (LC50,
ppm)
Further variations in the methylation of the rhamnose
sugar could also be obtained by the addition of
sinefungin (Chen et al., 1989), which in S. spinosa
specifically blocked the 4 0 -O-methyltransferase during
the fermentation process of the wild-type strain
(Sparks et al., 1996, 1999). When sinefungin was
added to fermentations of the H (nonfunctional 2 0 -
O-methyltranferase) and J (nonfunctional 3 0 -Omethyltranferase)
mutant strains, several other new
spinosyns (P, U, V, W) were produced that were
missing methyl groups from the 4 0 -position in combination
with missing methyl groups from either the
2 0 -or3 0 -positions (Sparks et al., 1996, 1999).
In general, the variations in all of the abovementioned
spinosyns center around (1) methylation
of the forosamine amino group, (2) presence or
absence of O-methyl groups on the rhamnose sugar,
Stomoxys
calcitrans,
adult
(LC50, ppm)
Aphis
gossypii
(LC50,
ppm)
Macrosteles
quadrilineatus
(LC50, ppm)
and (3) presence or absence of alkyl group(s) at the
C6, C16, and C21 positions of the tetracyclic ring
system. Other factors related to spinosyn A include
the C17 pseudoaglycone (PSA), which lacks the forosamine
sugar, the corresponding C9 PSA, missing
the rhamnose moiety, and the aglycone, where both
sugars are absent. The corresponding PSAs and
aglycone were also observed for spinosyn D (Table 1).
Through the above process of isolating major and
minor factors from the wild-type and mutant strains
of S. spinosoa, more than 20 different spinosyns
were identified (Sparks et al., 1996, 1999) (Table 1).
6.2.2. The 21-Butenyl Spinosyns
Tetranychus
urticae
(LC50, ppm)
Spinosyns
1 A 0.31 0.3–0.53 0.43 50 (42–88) 6.9 5.3
2 B 0.4 0.58 50 16
7 G 7.1
8 H 5.7 1.1 0.31 >50 >50
9 J >80 6.3 0.5 >50 63
10 A C17-pseudoaglycone >64 90 100
11 A C9-pseudoaglycone >64
12 A aglycone >64
13 D C17-pseudoaglycone >64 100
14 D C9-pseudoaglycone >64
15 D aglycone >64
7 H 5.7 1.1 0.31 >50 95
16 Q 0.5 1.8 0.26 >50 14
17 R 14.5
18 S 53 11.7 114
19 T >64 >10 >10 >100
8 J >80 6.3 0.5 >50 63
20 L 26 2.8 50 >100 48–67
21 M 22.6 >100
22 N 40 61 >50
23 K 3.5 2.9 1.7 12 3.2 1.4
24 O 1.4 50
27 V 17 2.8
28 P >64 >10 6.1
29 W >64
Cypermethrin 0.18
Ethofenprox 0.3
Fenazaquin 1.0
Like Eli Lilly and Company, Dow AgroSciences has
also had a long-standing natural products screening
program. During the mid-1990s a high-throughput