Table 1. Chemicals affecting crop muscle contractions in adult flies.

Species: 1-D. melanogaster; 2-P. regina; 3-M. domestica; Pumps/Valves based on Thomson [61].

Chemical	Effect on crop	Species	Pumps/Valves	References
Dromyosuppressin (DMS), TDVDHVFLRFamide	Negatively modulates contractions	1, 2	Lobes	[76–80]
Benzothonium (Bztc)	Mimics the myosuppressin effect of DMS	2, 3	Lobes	[80,81]
Serotonin (5-HT)	Increases activity of P4	2	P4	[26]
Drosulfakinins, drosulfakinin 0 (DSK 0)	Decreases contractions	1	Lobes	[82]
TPAEDFMRFamide	Decreases contractions	1	Lobes	[76,77,83]
AKH or Phote-HrTH (P. terraenovae hypertrehalosemic hormone)	Negatively modulates P4, but increases P5	2	P4, P5	[44]
Spider peptide toxin- GsMTx-4	Negatively modulates P5	2	P5	[11]
Trehalose	Increases P5 contractions	2	Lobes	[51,61]
Glucose	Reduces P5 contractions	2	Lobes	[51,61]
	Decreases rate of opening of V2, i.e. it requires more peristaltic waves in P3 to cause V2 to open	2	V2/P3	[58]
CavTachykinin, Callitachykinin-1	Increases rate of contractions V4/P6 but alters P5	2	V4/P6	[84]
Peptide flatline (FLT)	Reduces the number of lobe contractions	1	Lobes	[85]